Xanthogranulomatous Osteomyelitis Presenting as a Subacute Infectious Condition in the Fibula of a Young Female

Xanthogranulomatous osteomyelitis is a rare, chronic inflammatory disease characterized by infiltrating lipidized histiocytes, lymphocytes, and plasma cells. Xanthogranulomatous osteomyelitis commonly presents as a mass-like lesion on imaging and may be mistaken for a tumor. Here, we describe an unusual manifestation of xanthogranulomatous osteomyelitis with imaging findings resembling those of Brodie’s abscess, posing a diagnostic challenge in a child. Additionally, we suggest a potential correlation between xanthogranulomatous osteomyelitis and a history of prior trauma.

A Novel Magnetic Resonance Quality Assurance Phantom (KMRP-4):Multi-Site Comparison With the American College of Radiology Phantom

Purpose@#To propose a novel standard magnetic resonance imaging (MRI) phantom, hereafter called the Korea Magnetic Resonance Phantom-4th edition (KMRP-4). Its related quality control (QC) assessment protocols and its comparison with the American College of Radiology (ACR) phantom and its QC assessment protocols. @*Materials and Methods@#Internally, the KMRP-4 phantom is composed of cubic and triangular vessels, brain tissue structures, and a uniform region designed to facilitate a variety of QC protocols. Using magnetic resonance (MR) images of these structures, we quantitatively evaluated a total of 10 parameters, seven from those of existing ACR protocols (i.e., geometric accuracy, high-contrast spatial resolution, slice thickness accuracy, slice position accuracy, image intensity uniformity, percent signal ghosting, and low-contrast object detectability) and three additional parameters for evaluating vessel conspicuity, brain tissue contrast, and signal-to-noise ratio (SNR) introduced in the KMRP-4 protocols. Twentytwo MRI systems of 0.32–3.0 T static magnetic field strength were tested using both ACR and KMRP-4 phantoms. Mann–Whitney U-tests were performed on the seven evaluation items of the ACR method to compare KMRP-4 and ACR methods. @*Results@#The results of Mann–Whitney U-test demonstrated that p-values were more than 0.05 for all seven items that could be assessed with both ACR and KMRP-4, indicating similar results between the two methods. Additionally, assessments of vessel conspicuity, brain tissue contrast, and SNR using the KMRP-4 method demonstrated utility of the KMRP-4 phantom. @*Conclusion@#A novel standard phantom and related QC methods were developed to perform objective, observer-independent, and semi-automatic QC tests. Quantitative comparisons of MR images with KMPR-4 and ACR phantoms were performed. Results demonstrated the utility of the newly proposed KMRP-4 phantom and its related QC methods.

Extradural Spinal Lymphoplasmacyte-Rich Meningioma in the Thoracic Spine: A Case Report and Literature Review

Most spinal meningiomas have an intradural or partly extradural location. The meningothelial origin is the most common pathologic type of spinal meningioma. Pure extradural spinal meningiomas are not common, and lymphoplasmacyte-rich meningioma (LPRM) is very rare. We report a case of isolated extradural spinal meningioma in the thoracic spine that was pathologically confirmed as LPRM.

Early Imaging Findings of Hypertrophic Osteoarthropathy Mimicking Bone Metastasis from Extrathoracic Malignancy

Hypertrophic osteoarthropathy (HOA) is a syndrome characterized by digital clubbing, periosteal bone formation, and synovial effusions. Secondary HOA is associated with intrathoracic malignancy in most cases; however, in rare cases, HOA can be caused by extrathoracic conditions. We report early ultrasound, computed tomography, magnetic resonance imaging, and bone scintigraphy findings of HOA in a patient with breast cancer. Its ambiguous clinical and imaging findings that mimicked malignant conditions are particularly interesting and informative.

Depiction of the Periosteum Using Ultrashort Echo Time Pulse Sequence with Three-Dimensional Cone Trajectory and Histologic Correlation in a Porcine Model

Objective@#To evaluate the signal intensity of the periosteum using ultrashort echo time pulse sequence with threedimensional cone trajectory (3D UTE) with or without fat suppression (FS) to distinguish from artifacts in porcine tibias. @*Materials and Methods@#The periosteum and overlying soft tissue of three porcine lower legs were partially peeled away from the tibial cortex. Another porcine tibia was prepared as three segments: with an intact periosteum outer and inner layer, with an intact periosteum inner layer, and without periosteum. Axial T1 weighted sequence (T1 WI) and 3D UTE (FS) were performed. Another porcine tibia without periosteum was prepared and subjected to 3D UTE (FS) and T1 WI twice, with positional changes. Two radiologists analyzed images to reach a consensus. @*Results@#The three periosteal tissues that were partially peeled away from the cortex showed a high signal in 3D UTE (FS) and low signal on T1 WI. 3D UTE (FS) showed a high signal around the cortical surface with an intact outer and inner periosteum, and subtle high signals, mainly around the upper cortical surfaces with the inner layer of the periosteum and without periosteum. T1 WI showed no signal around the cortical surfaces, regardless of the periosteum state. The porcine tibia without periosteum showed changes in the high signal area around the cortical surface as the position changed in 3D UTE (FS). No signal was detected around the cortical surface in T1 WI, regardless of the position change. @*Conclusion@#The periosteum showed a high signal in 3D UTE and 3D UTE FS that overlapped with artifacts around the cortical bone.

Depiction of the Periosteum Using Ultrashort Echo Time Pulse Sequence with Three-Dimensional Cone Trajectory and Histologic Correlation in a Porcine Model

Objective@#To evaluate the signal intensity of the periosteum using ultrashort echo time pulse sequence with threedimensional cone trajectory (3D UTE) with or without fat suppression (FS) to distinguish from artifacts in porcine tibias. @*Materials and Methods@#The periosteum and overlying soft tissue of three porcine lower legs were partially peeled away from the tibial cortex. Another porcine tibia was prepared as three segments: with an intact periosteum outer and inner layer, with an intact periosteum inner layer, and without periosteum. Axial T1 weighted sequence (T1 WI) and 3D UTE (FS) were performed. Another porcine tibia without periosteum was prepared and subjected to 3D UTE (FS) and T1 WI twice, with positional changes. Two radiologists analyzed images to reach a consensus. @*Results@#The three periosteal tissues that were partially peeled away from the cortex showed a high signal in 3D UTE (FS) and low signal on T1 WI. 3D UTE (FS) showed a high signal around the cortical surface with an intact outer and inner periosteum, and subtle high signals, mainly around the upper cortical surfaces with the inner layer of the periosteum and without periosteum. T1 WI showed no signal around the cortical surfaces, regardless of the periosteum state. The porcine tibia without periosteum showed changes in the high signal area around the cortical surface as the position changed in 3D UTE (FS). No signal was detected around the cortical surface in T1 WI, regardless of the position change. @*Conclusion@#The periosteum showed a high signal in 3D UTE and 3D UTE FS that overlapped with artifacts around the cortical bone.

Subdural Hemorrhage Related to Vitamin K Deficiency in an Infant with Choledochal Cyst / 대한법의학회지

The deceased was a 6-month-old male infant who was transferred to the hospital due to jaundice and vomiting. During admission, subdural hemorrhage and retinal hemorrhage were observed; additionally, a rib fracture was identified on the previous radiography images, which had eventually healed by the time of the follow-up study. This case was reported to the police, alleging child abuse, which led to a medicolegal dispute between the hospital and the deceased's parents. In addition, bleeding tendency and coagulopathy related to vitamin K deficiency were also found. The past history revealed that the deceased had diarrhea, jaundice, and experienced several episodes of acholic stools, and low levels of vitamin D at birth. On postmortem examination, the brain already revealed liquefactive necrosis, but subdural hemorrhage was still observed. The optic nerves of both eyes revealed hemorrhage with focal retinal hemorrhage.No definite fracture was identified; however, osteopenia was observed in the long bones. The liver showed septal fibrosis and cholestasis which is nearly biliary cirrhosis, and mild dilation of the intrahepatic and extrahepatic bile ducts, suggesting a choledochal cyst. This case illustrates that subdural hemorrhage related to vitamin K deficiency could occur in an infant with a choledochal cyst.When subdural hemorrhage is encountered in a child with what is considered an intentional head injury, the possibility of spontaneous hemorrhage should be excluded.

Shear-Wave and Strain Ultrasound Elastography of the Supraspinatus and Infraspinatus Tendons in Patients with Idiopathic Adhesive Capsulitis of the Shoulder: A Prospective Case-Control Study

OBJECTIVE: To compare the elasticity of the supraspinatus tendon (SST) and infraspinatus tendon (IST) in patients with idiopathic adhesive capsulitis of the shoulder (ACS) with those in the control groups and to evaluate the relationship between age and tendon elasticity. MATERIALS AND METHODS: The Institutional Review Board approved this prospective, case-control study, which was conducted between November 2017 and March 2018, and informed consent was obtained from all participants. Control groups comprised healthy individuals or those with asymptomatic contralateral shoulders. Twenty-five shoulders in 20 participants in the ACS group (14 women; 53.5 ± 7.9 years) and 24 shoulders in 18 participants in the control group (6 women; 52.6 ± 10.5 years) were included. Elastography was performed in the oblique coronal plane at the neutral shoulder position. Mean/maximum/minimum velocity and stiffness from the shear-wave ultrasound elastography (SWE) and strain ratio (subcutaneous fat/target-tendon) from the strain ultrasound elastography (SE) of the SST and IST were evaluated. Statistical analyses were performed using the Mann-Whitney U test, receiver operating characteristic (ROC) curve, and Spearman correlation. RESULTS: Both velocity and stiffness in SWE were higher, and the strain ratio in SE was lower in participants with symptomatic shoulders than in those with normal shoulders (p 0.970). The elastic modulus was little correlated with age (ρ = −0.340–0.239). CONCLUSION: SWE and SE indicated that SST and IST were stiffer in patients with ACS than in those with normal shoulders regardless of aging.

Traumatic Rupture of the Middle Cerebral Artery Followed by Acute Basal Subarachnoid Hemorrhage: Tailored Approach in Forensic Pathology by Aid of Post-mortem Angiographic Findings / 대한법의학회지

We present the case of a 23-year-old man who suddenly collapsed during a physical altercation with his friends while in a drunken state. The post-mortem computed tomography (CT) with angiography revealed acute basal subarachnoid hemorrhage with rupture of the left middle cerebral artery. On autopsy, the head, face, mandible and neck showed multifocal hemorrhages with fracture of the hyoid bone, and the pathologic findings of the brain was consistent with CT findings. However, the vascular rupture site was not observed macroscopically. On histologic examination, a microscopic focal rupture was identified at the proximal portion of the middle cerebral artery, and possibility of arteriopathy was considered. This case illustrates that other parts of intracerebral arteries (other than the vertebral arteries) can be the culprit of rupture in the case of traumatic basal subarachnoid hemorrhage, and the post-mortem angiographic findings can be helpful in targeting the site of vascular injury. Furthermore, meticulous sampling of intracranial vessels could help find the vascular rupture site and identify any histologic findings suspicious of arteriopathy. Therefore, we suggest that post-mortem angiography can be an effective and adjunctive tool for a tailored approach in finding the vascular injury, and that histologic examination of both the intracranial and extracranial arteries be important to medicolegally ensure the death of traumatic basal subarachnoid hemorrhage and to examine presence of arteriopathy as a predisposing factor.

Traumatic Rupture of the Middle Cerebral Artery Followed by Acute Basal Subarachnoid Hemorrhage: Tailored Approach in Forensic Pathology by Aid of Post-mortem Angiographic Findings / 대한법의학회지

We present the case of a 23-year-old man who suddenly collapsed during a physical altercation with his friends while in a drunken state. The post-mortem computed tomography (CT) with angiography revealed acute basal subarachnoid hemorrhage with rupture of the left middle cerebral artery. On autopsy, the head, face, mandible and neck showed multifocal hemorrhages with fracture of the hyoid bone, and the pathologic findings of the brain was consistent with CT findings. However, the vascular rupture site was not observed macroscopically. On histologic examination, a microscopic focal rupture was identified at the proximal portion of the middle cerebral artery, and possibility of arteriopathy was considered. This case illustrates that other parts of intracerebral arteries (other than the vertebral arteries) can be the culprit of rupture in the case of traumatic basal subarachnoid hemorrhage, and the post-mortem angiographic findings can be helpful in targeting the site of vascular injury. Furthermore, meticulous sampling of intracranial vessels could help find the vascular rupture site and identify any histologic findings suspicious of arteriopathy. Therefore, we suggest that post-mortem angiography can be an effective and adjunctive tool for a tailored approach in finding the vascular injury, and that histologic examination of both the intracranial and extracranial arteries be important to medicolegally ensure the death of traumatic basal subarachnoid hemorrhage and to examine presence of arteriopathy as a predisposing factor.

Ultrasonographic Findings of Subcutaneous Angioleiomyomas in the Extremities Based on Pathologic Subtypes

OBJECTIVE: The purpose of this study was to describe the ultrasonographic findings of angioleiomyoma based on pathological subtypes. MATERIALS AND METHODS: Thirty-nine patients with subcutaneous angioleiomyomas in the extremities were retrospectively reviewed by two radiologists and a pathologist. Sonographic images were analyzed to evaluate each tumor's anatomic location, size, shape, margin, heterogeneity, echogenicity, associated findings, and vascularity. RESULTS: Angioleiomyomas were divided into 3 subtypes: capillary (n = 16), venous (n = 22), and cavernous (n = 1). The one cavernous angioleiomyoma was a hypoechoic mass with rich vascularity. Hypoechogenicity was more frequently observed for venous tumors (77.3%) than for capillary tumors (43.8%), and isoechogenicity was more frequently observed for capillary tumors (56.2%) than for venous tumors (22.7%). Moderate vascularity was more frequently observed for venous tumors (59.1%) than for capillary tumors (12.5%), and little vascularity was more frequently observed for capillary tumors (62.5%) than for venous tumors (13.6%). The aforementioned findings including echogenicity (p = 0.034) and vascularity (p = 0.003) were statistically significant. CONCLUSION: Awareness of sonographic findings of angioleiomyomas based on pathologic subtypes could be helpful for diagnosing angioleiomyoma and could increase diagnostic accuracy for superficial soft-tissue masses in our practice.

Analyzing correlation between epicardial fat area and metabolic syndrome risk factor by using low-dose Lung CT

To study about the blood count of a risk factor related to physical measurement and metabolic syndrome, and the area of epicardial fat for medical checkup patients. From April 1[st]t to November 15[th] in 2014, we measured the area of epicardial fat in the adult out patients under 60 years of age, who are in good health; and the patients took the blood test and low-dose lung CT. In order to identify the relationship between the area of epicardial fat and the risk factor of metabolic syndrome, we conducted correlation analysis. Then, we performed multiple regression analysis to evaluate an independent correlation of epicardial area. In addition, we computed the cut-off value of epicardial fat area by using ROC [Receiver Operating Characteristic curve to foresee a metabolic syndrome factor that has the most proper sensitivity and specificity. aist circumference, fasting blood sugar, triglyceride, high-density lipoprotein [HDL] cholesterol, systolic blood pressure, and diastolic blood pressure were shown to be the factors that affect the area of epicardial fat. Therefore, if waist circumference, fasting blood sugar, triglyceride, systolic blood pressure, and diastolic blood pressure were increased, the area of epicardial fat would be significantly increased [P<0.05]; and if high-density lipoprotein cholesterol was increased, the area of epicardial fat would be significantly decreased [P<0.05]. Out of metabolic syndrome factors, waist circumference's ROC curve area was 0.79 [Confidence Interval 0.73-0.84, P<0.05], which was the highest. The sensitivity was 83.7% when specificity was 70.1%, which proves that they are important factors for the diagnosis. In brief, metabolic syndrome is a disease that mostly appears in obesity patients, so we should try to monitor and cure the disease. The risk factors of metabolic syndrome can be managed through health care, and if we try to decrease the risk factors, we will be able to shrink epicardial fat area and decrease metabolic syndrome at the same time

Myocardial Contrast Defect Associated with Thrombotic Coronary Occlusion: Pre-Autopsy Diagnosis of a Cardiac Death with Post-Mortem CT Angiography

We report the case of a female who died of suspected acute myocardial infarction. Post-mortem CT angiography (PMCTA) was performed with intravascular contrast infusion before the standard autopsy, and it successfully demonstrated the complete thrombotic occlusion of a coronary artery and also a corresponding perfusion defect on myocardium. We herein describe the PMCTA findings of a cardiac death with special emphasis on the potential benefits of this novel CT technique in forensic practice.

Lumbosacral Plexopathy Caused by Presacral Recurrence of Colon Cancer Mimicking Degenerative Spinal Disease: A Case Report

Radiculopathy triggered by degenerative spinal disease is the most common cause of spinal surgery, and the number of affected elderly patients is increasing. Radiating pain that is extraspinal in origin may distract from the surgical decision on how to treat a neurological presentation in the lower extremities. A 54-year-old man with sciatica visited our outpatient clinic. He had undergone laminectomy and discectomy to treat spinal stenosis at another hospital, but his pain remained. Finally, he was diagnosed with a plexopathy caused by late recurrence of colorectal cancer, which compressed the lumbar plexus in the presacral area. This case report illustrates the potential for misdiagnosis of extraspinal plexopathy and the value of obtaining an accurate history. Although the symptoms are similar, spinal surgeons should consider both spinal and extraspinal origins of sciatica.

Imaging of Herniated Discs of the Cervical Spine: Inter-Modality Differences between 64-Slice Multidetector CT and 1.5-T MRI

OBJECTIVE: To assess inter-modality variability when evaluating cervical intervertebral disc herniation using 64-slice multidetector-row computed tomography (MDCT) and magnetic resonance imaging (MRI). MATERIALS AND METHODS: Three musculoskeletal radiologists independently reviewed cervical spine 1.5-T MRI and 64-slice MDCT data on C2-3 though C6-7 of 51 patients in the context of intervertebral disc herniation. Interobserver and inter-modality agreements were expressed as unweighted kappa values. Weighted kappa statistics were used to assess the extents of agreement in terms of the number of involved segments (NIS) in disc herniation and epicenter measurements collected using MDCT and MRI. RESULTS: The interobserver agreement rates upon evaluation of disc morphology by the three radiologists were in fair to moderate agreement (k = 0.39-0.53 for MDCT images; k = 0.45-0.56 for MRIs). When the disc morphology was categorized into two and four grades, the inter-modality agreement rates were moderate (k-value, 0.59) and substantial (k-value, 0.66), respectively. The inter-modality agreements for evaluations of the NIS (k-value, 0.78) and the epicenter (k-value, 0.79) were substantial. Also, the interobserver agreements for the NIS (CT; k-value, 0.85 and MRI; k-value, 0.88) and epicenter (CT; k-value, 0.74 and MRI; k-value, 0.70) evaluations by two readers were substantial. MDCT tended to underestimate the extent of herniated disc lesions compared with MRI. CONCLUSION: Multidetector-row computed tomography and MRI showed a moderate-to-substantial degree of inter-modality agreement for the assessment of herniated cervical discs. MDCT images have a tendency to underestimate the anterior/posterior extent of the herniated disc compared with MRI.

Retrieval Rate and Accuracy of Ultrasound-Guided 14-G Semi-Automated Core Needle Biopsy of Breast Microcalcifications

OBJECTIVE: To evaluate the retrieval rate and accuracy of ultrasound (US)-guided 14-G semi-automated core needle biopsy (CNB) for microcalcifications in the breast. MATERIALS AND METHODS: US-guided 14-G semi-automated CNB procedures and specimen radiography were performed for 33 cases of suspicious microcalcifications apparent on sonography. The accuracy of 14-G semi-automated CNB and radiology-pathology concordance were analyzed and the microcalcification characteristics between groups with successful and failed retrieval were compared. RESULTS: Thirty lesions were successfully retrieved and the microcalcification retrieval rate was 90.9% (30/33). Thirty lesions were successfully retrieved. Twenty five were finally diagnosed as malignant (10 invasive ductal carcinoma, 15 ductal carcinoma in situ [DCIS]) and five as benign. After surgery and mammographic follow-up, the 25 malignant lesions comprised 12 invasive ductal carcinoma and 13 DCIS. Three lesions in the failed retrieval group (one DCIS and two benign) were finally diagnosed as two DCIS and one benign after surgery. The accuracy of 14-G semi-automated CNB was 90.9% (30/33) because of two DCIS underestimates and one false-negative diagnosis. The discordance rate was significantly higher in the failed retrieval group than in the successful retrieval group (66.7% vs. 6.7%; p < 0.05). Punctate calcifications were significantly more common in the failed retrieval group than in the successful retrieval group (66.7% vs. 3.7%; p < 0.05). CONCLUSION: US-guided 14-G semi-automated CNB could be a useful procedure for suspicious microcalcifications in the breast those are apparent on sonography.

The Difference in Diagnostic Performance for Detection of Supraspinatus Tendon Tears by Adding Angled Oblique Sagittal Plane Image to the Routine Shoulder MRI

PURPOSE: The purpose of this study is to determine whether adding an angled oblique sagittal plane to the routine shoulder MRI improves the diagnostic performance in the evaluation of supraspinatus tendon tears with arthroscopic correlation. MATERIALS AND METHODS: The study included 121 patients who had a shoulder MRI followed by arthroscopy. Two radiologists separately evaluated the supraspinatus tendon for tears on shoulder MRI either with or without the angled oblique sagittal images. Arthroscopy was used as the reference standard. The sensitivity and specificity for diagnosing supraspinatus tendon tears were calculated and compared by using McNemar test. Interobserver and intertechnique variability in the interpretation of supraspinatus tendon tears were calculated as a kappa value. RESULTS: Adding the angled oblique sagittal images to the standard shoulder MRI showed improvement in the sensitivity for diagnosing full-thickness supraspinatus tendon tears and also in the sensitivity, specificity and accuracy for the detection of partial-thickness tears. However, there was no statistically significant difference in all of them between with and without the angled set. Interobserver agreement was substantial to almost perfect and intertechnique agreement was moderate. CONCLUSION: Adding an angled oblique sagittal plane image to the routine shoulder MRI showed no significantly different diagnostic performance in detecting the partial- and full-thickness supraspinatus tendon tears, compared to MRI without angled oblique sagittal plane.

Comparison of Three-Dimensional Isotropic and Two-Dimensional Conventional Indirect MR Arthrography for the Diagnosis of Rotator Cuff Tears

OBJECTIVE: To compare the accuracy between a three-dimensional (3D) indirect isotropic T1-weighted fast spin-echo (FSE) magnetic resonance (MR) arthrography and a conventional two-dimensional (2D) T1-weighted sequences of indirect MR arthrography for diagnosing rotator cuff tears. MATERIALS AND METHODS: The study was approved by our Institutional Review Board. In total, 205 patients who had undergone indirect shoulder MR arthrography followed by arthroscopic surgery for 206 shoulders were included in this study. Both conventional 2D T1-weighted FSE sequences and 3D isotropic T1-weighted FSE sequence were performed in all patients. Two radiologists evaluated the images for the presence of full- or partial-thickness tears in the supraspinatus-infraspinatus (SSP-ISP) tendons and tears in the subscapularis (SSC) tendons. Using the arthroscopic findings as the reference standard, the diagnostic performances of both methods were analyzed by the area under the receiver operating characteristic curve (AUC). RESULTS: Arthroscopy confirmed 165 SSP-ISP tendon tears and 103 SSC tendon tears. For diagnosing SSP-ISP tendon tears, the AUC values were 0.964 and 0.989 for the 2D sequences and 3D T1-weighted FSE sequence, respectively, in reader I and 0.947 and 0.963, respectively, in reader II. The AUC values for diagnosing SSC tendon tears were 0.921 and 0.925, respectively, for reader I and 0.856 and 0.860, respectively, for reader II. There was no significant difference between the AUC values of the 2D and 3D sequences in either reader for either type of tear. CONCLUSION: 3D indirect isotropic MR arthrography with FSE sequence and the conventional 2D arthrography are not significantly different in terms of accuracy for diagnosing rotator cuff tears.

18F-FDG PET/CT in the Clinical Assessment of Patients with Multiple Myeloma: A Pilot Study / 대한내과학회지

BACKGROUND/AIMS: This study investigated the clinical utility of positron emission tomography/computed tomography (PET/CT) for evaluating bone lesions in patients with multiple myeloma before therapy. METHODS: Whole-spine and pelvic magnetic resonance imaging (MRI) and whole-body PET/CT were conducted in patients newly diagnosed with multiple myeloma before therapy. We compared the PET/CT and MRI results for the entire spine and pelvis, and the discordance rates were cross-analyzed with the clinical factors. RESULTS: Ten patients were enrolled (median age 57.5 years). The majority were at an advanced stage, and IgG type multiple myeloma occurred in seven patients. All patients underwent PET/CT and 36 sites were checked on MRI. Approximately 69% of the patients had diffuse patterns, 8.3% had focal lesions, 5.6% had mixed lesions, and 16.7% had a normal pattern on MRI. The concordance rate of PET/CT compared with MRI was 83.3% (30 sites). The false-positive rate was 13.9% and the false-negative rate was 2.8%. No factor predicted the discordance between the PET/CT and MRI results. CONCLUSIONS: A well-designed, large-scale study is warranted to confirm the accuracy of PET/CT for detecting bone lesions in these patients.

Practical Application of Iterative Decomposition of Water and Fat with Echo Asymmetry and Least-Squares Estimation (IDEAL) Imaging in Minimizing Metallic Artifacts

Iterative decomposition of water and fat with echo asymmetry and the least-squares estimation (IDEAL) is a recently developed method for robust separation of fat and water with very high signal-to-noise-ratio (SNR) efficiency. In contrast to conventional fat-saturation methods, IDEAL is insensitive to magnetic field (B0 and B1) inhomogeneity. The aim of this study was to illustrate the practical application of the IDEAL technique in reducing metallic artifacts in postoperative patients with metallic hardware. The IDEAL technique can help musculoskeletal radiologists make an accurate diagnosis particularly in musculoskeletal imaging by reducing metallic artifacts, enabling the use of contrast enhancement, improving SNR performance, and providing various modes of MR images with one scan parameter.